This invention relates to an apparatus for treating radioactive materials by solidifying them, and more particularly to a solidification processing apparatus for solidifying radioactive waste materials in powdery, granular or indefinite forms in a treating vessel to form stable solidified bodies suitable for keeping, storing or disposing.
Various kinds of radioactive waste materials produced in nuclear power installations such as nuclear power stations are usually stored in the respective installations. Various kinds of solidification processing methods have been proposed or actually used for reducing volume of the waste materials and ensuring their stability in consideration of saving storage spaces as well as safety, transportation and future disposal of the waste materials.
There have been known solidification processing methods for the radioactive waste materials, such as solidifying them with cement or solidifying them by mixing with melted asphalt or plastic material or the like. As an improved method of the above methods, it has been recently proposed to melt radioactive waste materials so as to be solidified in glass or together with melted glass or to solidify radioactive waste materials by cement glass.
In the method of solidifying radioactive waste materials with cement, asphalt or plastic material, however, it is necessary to knead the radioactive waste materials with the solidifying agent such as the cement, asphalt or plastic material after the waste materials have been crushed or pulverized. In the solidification method by the cement glass, moreover, it is necessary to make the radioactive waste materials into pellet forms or to knead the materials with the solidifying agent after crushing or pulverizing the materials. These operations are not preferable as handling operations for the radioactive waste materials, because for example crushers, kneading extruders or pellet forming machines are needed. In the method of solidifying the radioactive waste materials together with glass, the materials are once melted and solidified in glass, or the materials are mixed with melted glass and then solidified together with the glass. Therefore, melting installations required for melting the materials and the glass are very expensive in operation. Moreover, in the case of waste material apt to thermally decompose, an additional installation is needed for treating gases produced in the decomposition.